24 July 2021 HAYNES®
Haynes 25 Nickel Based Superalloy
HAYNES® 25 alloy (UNS R30605) is a cobalt-nickel- chromium-tungsten alloy that combines excellent high-temperature strength with good resistance to oxidizing environments up to 1800°F (980°C) for prolonged exposures, and excellent resistance to sul dation. It can be fabricated and formed by conventional techniques, and has been used for cast components. Other attractive features include excellent resistance to metal galling.
Haynes 25 corresponds to China's GH605 cobalt-based superalloy. This alloy is a 20Cr and 15W solid solution strengthened cobalt-based superalloy. It has medium endurance and creep strength below 815°C and excellent oxidation resistance below 1090°C. , At the same time, it has satisfactory processing performances such as forming and welding. It is suitable for the manufacture of aero-engine combustion chambers and guide vanes that require medium strength and excellent high-temperature oxidation resistance. It can also be used on aero engines and space shuttles. Mainly used on imported models to manufacture high-temperature parts such as guide fins, turbine outer rings, outer walls, vortex devices, and sealing fins.
Chemical Composition:
| Ni | Cr | Mn | Si | Fe | S | Co |
|---|---|---|---|---|---|---|
| 11.00 | 21.00 | 2.00 | 0.40 | 3.00 | 0.030 | Bal |
| 9.00 | 19.00 | 1.00 |
Mechanical Properties:
| Ultimate Tensile | Yield Strength (0.2% OS) | Elong. in 4D % | R/A | Hardness | |
|---|---|---|---|---|---|
| Min | 125 Ksi | 45.0 KSi | 30 | ||
| Max | |||||
| Min | 862 Mpa | 310 MPa | |||
| Max |
Fabrication:
HAYNES® 25 alloy has good forming and welding characteristics. It may be forged or otherwise hot-worked, providing that it is held at 2200°F (1205°C) for a time suf cient to bring the entire piece to temperature. The alloy has good ductility, and thus also may be formed by cold working. The alloy does work-harden very rapidly, however, so frequent intermediate annealing treatments will be needed for complex component forming operations. All hot- or cold-worked parts should be annealed and rapidly cooled in order to restore the best balance of properties. The alloy can be welded by both manual and automatic welding methods, including gas tungsten arc (GTAW), gas metal arc (GMAW), shielded metal arc, electron beam and resistance welding. It exhibits good restraint welding characteristics.
Heat Treatment:
Wrought HAYNES® 25 alloy is furnished in the solution heattreated condition, unless otherwise speci ed. The alloy is normally solution heat-treated at 2150 to 2250°F (1175 to 1230°C) and rapidly cooled or water-quenched for optimal properties. Annealing at temperatures less than the solution heat-treating temperature will produce some carbide precipitation in 25 alloy, which may affect the alloy’s properties.
Applications:
HAYNES® 25 alloy combines properties which make it suitable for a number of component applications in the aerospace industry, including parts in established military and commercial gas turbine engines. In modern engines, it has largely been replaced by newer materials such as HAYNES® 188 alloy, and, most recently, 230® alloy, which possess improved properties. Another area of signi cant usage for 25 alloy is as a bearing material, for both balls and races.